Please answer each bullet regarding a chromatography lab expirement as thoroughl

Question

Please answer each bullet regarding a chromatography lab expirement as thoroughly as possible.

Question 3: Components were separated adeqautely.

Question 4: Hexanes only were used to obtain the yellow band in column chromatography. 70% hexane and 30% acetone was used to obtain the green band. It says switch to acetone if you need more solvent to collect the green band. Draw a reaction to show why.

In terms of the paper itself, why would a compound have a lower Rf value than another compound? Group 1 runs a pure sample via paper chromatography for 2 minutes. Group 2 runs the same pure sample for only 1 minute. Do they calculate the same Rfvalue? Why or why not? Were you able to adequately separate the components of your spinach using column chromatography? If not, give reasons why. Which method of chromatography can be done on a larger scale and allow a reclaiming of the pure component? Why does your lab manual suggest that you should "switch to acetone if you need more solvent to collect the green band" during your column chromotography? Use a CHEM DRAW structure to help explain. The reaction show below is monitored via chromatography, using a solvent system of 4:1 hexanes: ethyl acetate in the development chamber. Accordingly, a chromatogram is developed at a certain time during the reaction. (a) Is compound A or compound B more polar? (b) Was the chromatogram developed at the beginning, the middle, or at the end of the reaction How do you know 5 mol Dy(OTf)3 MeCN, 30 min. Product Ro 0.80 Rr 0.48 Rr 0.48 Rt 0.21 Rt 0.21 Rxnn

Explanation / Answer

1) the Rf values depends upon the binding ability of the solute on the stationary phase and the affinity for mobile phase.

More the affinity for mobile phase more the Rf value of the compound

2) The Rf value is calculated as

Rf = the vertical distance moved by the chemical from the spot / divided by the distance traveled by the solvent

So if we will change time then the Rf value will not change

3) The method of chromatography which can be done on larger scale is column chromatography

4) we are using non polar solvent so the Rf value of the compound which is less polar will be more

Here the compound A will be more polar

The chromatograph is developed at the middle of reaction as we are getting the spot for both the reactants as well the product.

At the start of reaction we will obtain spot for only A and B

At the end of reaction we will obtain spot for product only

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